package net;


import java.io.IOException;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.ServerSocket;
import java.net.SocketException;
import java.nio.charset.StandardCharsets;

public class UdpSer {
    private DatagramSocket socket =null;
    public UdpSer(int port) throws SocketException {
        socket = new DatagramSocket(port);
    }
    public void start() throws IOException {
        System.out.println("服务器启动!");
        while(true){
            //接收请求并解析
            DatagramPacket requestPacket = new DatagramPacket(new byte[4096],4096);
            socket.receive(requestPacket);
            String request = new String(requestPacket.getData(),0,requestPacket.getLength());
            String response = process(request);
            DatagramPacket responsePacket = new DatagramPacket(response.getBytes(),response.getBytes().length,
                    requestPacket.getSocketAddress());
            //发送请求
            socket.send(responsePacket);
            //打印日志
            System.out.printf("[%s : %d],req=%s,resp=%s",requestPacket.getAddress(),requestPacket.getPort()
            ,request,response);
        }
    }

    private String process(String request) {
        return request;
    }
}
